Distance between the medialis angles of the eyes as an anatomical parameter for tooth selection

During the construction of a removable prosthesis, the lack of pre-extractions records turns the selection of artificial maxillary anterior teeth into a complex procedure. The aim of this study was to identify a mathematical relation between the anterior dental segment and the distance between the medialis angles of the eyes, for selecting the suitable width of the six maxillary anterior teeth. Standardized digital images of 80 dentate Brazilian subjects were used to measure both facial and oral structures when viewed from the frontal aspect through an image processing program. Accurate casts were made to measure on a curve the distance between the maxillary canines. Parametric statistics was performed to analyse the results (P < 0.05). The distance between the medialis angles of the eyes showed no significant difference according to gender (P < 0.108). The Pearson Product Moment Correlation Coefficient showed significant positive correlation between the distance between the medialis angles of the eyes and all variables compared. After the linear regression analysis, mathematical formulae and biometric ratios were concluded to estimate the combined width of the six maxillary anterior teeth from the measurement of the distance between the medialis angles of the eyes. The distance between the medialis angles of the eyes measured through photogrammetry can be a reliable guide for tooth selection.